Direct airborne particulate and bioaerosol capture using suspended liquid surfactant membranes for continuous biodetection and threat analysis

Infectious airborne diseases are an enormous socioeconomic burden with impacts that span plant, animal and human health. Technology capable of collecting and seamlessly detecting the presence of pathogens have yet to reach maturity rendering aerosol dispersion as a disease vector particularly challenging to mitigate. To date there is no widespread use of sentinel or monitor systems to mitigate airborne disease transmission, pushing the burden of disease prevention onto diagnostic approaches and post disease infection control measures, as witnessed during the SARS-CoV-2 pandemic. The ability to continuously monitor air samples and identify new and emerging risks has the potential to deliver early warning and inform decision making prior to infection, providing enhanced protection for a wide variety of use cases in environmental, civilian and military settings.

The vision for this research programme is to take a leap forward in high-concentration, low-loss, aerosol capture for biodetection purposes through the development of a liquid membrane system that directly captures airborne material into a fluid that can be readily sampled for rapid downstream analysis. Resolving this has application towards airborne monitoring across a range of indoor and outdoor settings.

Flexible liquid surfactant membranes are wholly untested for aerosol collection and detection. There are several engineering challenges to overcome in the setup and stabilisation of surfactant membranes in addition to the added complexity of particle capture from air moving over the membrane. The two core engineering challenges for this research are, firstly, the ability to reliably generate, sustain and subsequently manage the collapse of a liquid film membrane (LiMEM) that has a composition that is biocompatible with downstream analysis tools such as molecular diagnostic (qPCR, LAMP) or immunoassay-based detection (LFA etc). The second, and perhaps more ambitious aspect of this research is the suspension of the LiMEM within an airflow to efficiently capture and retain aerosol material.

Addressing these engineering challenges would yield a tool that can combat the transmission of pathogenic aerosols, leading to increased confidence in defence settings, identification of new and emerging environmental disease risks or halting the spread of Healthcare Associated Infection (HCAI) in hospital and care settings.

The proposed research plan is divided into phases to address the underlying engineering challenges. Over 24 months we will develop a proof of principle platform to validate the LiMEM concept as a potential component in a fully integrated platform for collection, analysis and identification and quantification of harmful biological aerosols. The system will be benchmarked against known biowarfare aerosol analogs (inert/aerodynamic: Polystyrene (PSL) microspheres, bacterial spore: Bacillus Atrophaeus, protein/toxin: ovalbumin) so that the resultant data can be compared reliably to other recent biodetection advances developed by the UH group for the UK MoD (e.g. ESP/Electrowetting platforms).

Driven by the combined vision of aerosol detection specialists, environmental engineering experts and with input from infection control and management experts, this highly ambitious project aims to deliver a new method to providing transformative real-time low cost environmental bioaerosol monitoring technology.